How to fix a GitHub clone after the remote 'master' branch has been renamed to 'main'

git-rename-local-master-to-main.sh

# (Instructions are based on the "What Your Teammates Have to Do" section
# in https://www.git-tower.com/learn/git/faq/git-rename-master-to-main.)

# Switch to the "master" branch:
$ git checkout master

# Rename it to "main":
$ git branch -m master main

# Get the latest commits (and branches!) from the remote:
$ git fetch

# Remove the existing tracking connection with "origin/master":
$ git branch --unset-upstream

# Create a new tracking connection with the new "origin/main" branch:
$ git branch -u origin/main